Wireless Data Communications

 

WIRELESS LANS AT UM

The current wireless LAN environment at UM is compliant with the 802.11b/g standard. This standard allows for data transmission between workstations and wireless access points at 11Mbps (802.11b) or 54Mbps (802.11g). In areas where 802.11g access points are installed, the speed of data transmission automatically adjusts to allow compatibility between the associated client workstations.  When signal strength diminishes due to distance between the workstation and access point, speeds of 5.5MB, 2MB and 1MB are also supported. The access points connect to the UM network via 10/100MB Ethernet with the building’s switch.  In those areas where the network has not yet been upgraded to switch technology, the building’s infrastructure must be upgraded before wireless access points can be installed.

HOW TO OBTAIN A WIRELESS INSTALLATION

If a department/area is interested adding wireless network connectivity, Computer Services must be contacted to request an estimate for wireless installation costs. Computer Services will then perform a site survey to determine the number and placement of wireless access points, antenna types, etc. so as to provide an accurate cost estimate and provide optimum performance for the area. Computer Services will need to know the exact areas that are desired to be covered as well as the estimated number of simultaneous users within each area. Building construction may have an impact on the installation costs, and can only be accurately estimated after the site survey.

STANDARD FOR WIRELESS INSTALLATIONS

Computer Services has developed a set of standards for the deployment of Wireless LANs on the UM campus.  These standards will continue to evolve as wireless LAN products evolve. These standards are intended to:

• Allow for maximum possible flexibility and enable Computer Services to provide campus-wide wireless infrastructure.
• Prevent conflicts in frequency usage between departments/areas.
• Allow for roaming within buildings without loss of signal.
• Prevent unauthorized access to campus network.
• Make use of common standards to maximize product choices and supported platforms.

All wireless LAN installations on the UM campus must be coordinated by Computer Services. The following standards must be adhered to for all IEEE 802.11b/g compliant wireless LAN installations.  Any access points detected on campus that are not University-owned and coordinated by Computer Services will be deemed “rogue” and disconnected from the University’s network immediately.

1. HARDWARE

At this point in time, access points must be Cisco Aironet 1100 Series or HP Procurve 420 Series (or above) access points with the appropriate accessories for providing power.

All new wireless cards must support 128 bit encryption and open authentication, with the recommended card being the Cisco Aironet 350 Series Client Adapter (supports only 802.11b) or the Linksys, a Division of Cisco System, Wireless-G adapter (support 802.11b/g). Computer Services has tested 128 bit cards from Apple, DLink, Orinoco (Lucent) and Dell True Mobile and found that they function properly with the Cisco access points.

2. DHCP

All wireless users will obtain their IP address dynamically. Computer Services requires that the access points be set to pass DHCP requests to the central UM DHCP servers. To connect to a wireless access point and obtain an IP address via DHCP, the user’s MAC address may need to be registered in the NetReg database.  Non-University owned machines will need to be registered every Spring, Summer, and Fall semester to insure validity of registered data.

3. ENCRYPTION

Wireless encryption provides "Wire Equivalent Protection" (WEP) for transmitted data. All wireless transmissions will be encrypted using 128 bit or 40/64 bit encryption (64 bit encryption is the same as 40 bit).

4. ACCESS POINT PASSWORD

The access point read/write password must be changed from the factory default on all access points. Computer Services will assign and maintain passwords. In certain cases, departmental/area personnel may be granted read privileges to access point log information.  This will be granted after review of a written request for this access submitted by the individual’s department head/chair.  This request can be submitted via email to the Network Administrator.

5. CHANNEL ASSIGNMENTS

The 802.11b specification provides 11 channels, but these overlap, so at most three channels can be used in the same space. On the UM campus, channels 1, 6, and 11 will be used and will be assigned to access points by Computer Services. Channels other than 1, 6, and 11 should not be used at the University, as they might interfere with compliant infrastructure.

6. INTERFERENCE

Given the nature of wireless technology and the fact that 802.11b/g operates in the 2.4Ghz spectrum, interference with the wireless network can occur by devices operating within the same radio frequency.  For that reason, the use of 2.4Ghz wireless phones are prohibited on the UM campus. 

7. SSID

All access points' SSIDs will be configured such that mobile users can configure their cards to access all UM access points. Computer Services will supply a user with the SSID needed for their area and this information must be kept confidential.  All non-University owned computers and network devices will use the SSID “UMNET” and will need to be registered via the University network registration (NetReg) process.

8. RECOMMENDATIONS

• Submit a request to have Computer Services perform a comprehensive site survey if wireless connectivity is desired
  
  Wireless LANs are limited in speed, bandwidth and coverage. The 11Mbps speed of an 802.11b and 54Mbps of an 802.11g LAN is the total speed of all users sharing the same access point. A site survey will help to estimate the number of access points needed to cover the desired area at a given level of performance. Optimum access point location and/or antenna type can only be determined by a comprehensive site survey.
   
• Compliment the wired infrastructure
  
  The use of a hard wired connection may be preferred because it is faster and does not take bandwidth from other wireless stations. This is especially important where high bandwidth applications, such as video conferencing, are to be used.  Wireless LANs, however, may be a more cost effective solution when considering upgrading and/or expanding network connectivity in a specific area.

CURRENT WIRELESS LOCATIONS ON CAMPUS

• Anna Irvin Dining Hall
• Baseball field
• Bloch Hall
• Brooke Hall
• Calkins Hall
• Carmichael Library
• Child Study Center
• Comer Hall
• Davis Hall
• Farmer Hall
• Hanson Hall
• Harman Hall
• Hill House
• International House
• Jeter Hall
• King House
• Lund Hall
• Lyman House
• Main Hall
• Mass Communications
• Meroney House
• Morgan Hall
• Myrick Hall
• Palmer Hall (office areas)
• Peck Hall
• Ramsay Conference Center
• Reynolds Hall (partial coverage in ground floor classrooms)
• Student Activity Center
• Tower
• Tutwiler Hall
• Wallace Hall
• Wills Hall

WIRELESS CONNECTIVITY MAPS

The wireless connectivity map was updated in the early 2009 to provide an improved guide to wireless signal strength across the Montevallo campus.

 

(Note: in order to view this map, you will need to have Adobe Acrobat Reader® installed on  your computer.  Adobe Acrobat is available for no charge download here at http://www.adobe.com/products/acrobat/readstep2.html.)

Please contact the Computer Services Help Desk at (205) 665-6520 or via email at helpdesk@montevallo.edu with any questions.

Updated February 2009